On the landing roll out, the safest time to deviate from the centerline is when firm directional control is available. At a brisk walk directional control has already been lost. A good technique is to move to the side while above 20 k at a shallow angle to the runway, parallel the runway. The inertia of the glider will keep it away from the flight line after directional control is lost. If a direction change is being made during the lower speed when directional control is lost the inertia of the tail will take the student into the flightline. That happened at SSI. The student broke the canopy with his forehead. The high energy landings are likely caused by inability to fly to a aimpoint.
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